P0421 code after replacing center part of the exhaust

2008 MAZDA 6
96,000 MILES • 2.5L • 4 CYL • 2WD • MANUAL
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TOMBSMITH
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I recently had the center part of the exhaust changed then two days later got this catalytic converter error code. Could the two be related as they are part of the same system? Would prefer to get the work fixed under guarantee if possible.
Dec 3, 2018 at 10:46 AM
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ASEMASTER6371
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Good afternoon,

I listed the possibilities below.

Do you have any exhaust leaks?

What kind of converter did they use as a replacement?

Roy

P0421
Descriptor
Probable Causes
Exhaust System Leakage
Loose Front Oxygen Sensor (O2)
Loose Middle Oxygen Sensor (O2)
Loose Rear Oxygen Sensor (O2)
Other DTC's
Powertrain Control Module (PCM)
Three Way Converter (TWC) Deterioration
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Attached Media
Attached Media
Dec 3, 2018 at 10:58 AM